Double-wall pipe



Vparts assembled.

Patented July 1, 1930 "UNITE-Di.' STATES PATENT OFFICE-ff" wIIiLIAi/I` T. TRUnX, @BATTLE-canali, MciiIGAm AssIGNon To UNITED sTATnsj REGISTER co., 0F BATTLE canna, MICHIGAN, A CORPORATION 0F ifIIc'HIefAN j f i, iJoBLE-wem. PIPE lAppliefitioaineaIammlryf25, 192s. seri-a1 No. 2495380.' n

This inventionrelates to double walled hot air'pipes'that' are made in joints or sections and coupled together.. telescopically the external-end portion ofone section or piece V.being received'and engagedv b-y vthe the 'internal edge portion of thenext piece; Such pipes as ordinarily y'fashioned are in relatively short lengths and are intended to be connected one to another without Vthe use of tools, and to form a hot air conduit of any desired length.

rlhe object oft-his invention is the duction of a piece of double walled ypipe of the nature stated which has parts of special construction and arrangement providing a. joint easily and quickly connected or disconnected without the use of tools or expert knowledge of the subject, and'which will secure the joints of pipe together in suoli manner as to prevent any loss of warm air and afford a smooth uninterrupted interior channel for the passage of the air.

In the acompanying drawings the special construction andv arrangement of the par` ticular parts of this invention are illustrated,l

Fig. 1 represents a side view of one end of a piece of double walled pipe lformed in accordance with this invention and shows all vFig. 2 is atop vil w ofthe partssetout in Fig. 1.

Fig. 3 1s a vertical section on the broken line 3 3 of Fig. 1 showingtwo pieces of pipe made in accordance with this invention and joined together.

Y rhroughout the drawings anddescription the same number is used to referto the saine part.

Considering the drawings, each piece of pipe hasa plane outer Wall 1 and a plane inner wall joined together usually by a crimped edge y2 that bounds the opening of the pipe. Near the crimped edge 2 the wall 1 has a limited area of corrugations 3, li, 5, 6, adjacent hc end 7 which has also coresponding corrugations 8, 9, 10, 11 and 12. lt will be understood that the piece or section of pipe illustrated has two ends such asthe end 7, and at both ends are found corrugations innature and extent such as those set forth in Fig. 1.

In other `words the ends ofthe piece of pipe are exactduplicates so far as the construction isconcerned.`

At a distance below the'edge 2 will bey noted i a flat,v shoulder 13 and this shoulder Vpasses all around the pipe externally.v Just below the shoulder is a bead or rounded projection 14, cro-extensive with the shoulder. f

rliliesides ofthe piece ofpipey are greater in length than the pipe is wide, usually several times greater', and the customary cross- .sectionalshape of the pipe is rectangular as illustrated.` On each side of the pipe'belowY the edge 2. is formed a projecting inclined lip The lips are designated. by reference numbers 15 and 16. It will be notedinFig.

'2 that the end 17 of thev lip 16 diminishes-in width'towards they end ofthe pipe-and the 1 lip 15 also diminishes in` like manner. The

ends of the lipsare thus formed at both ends of 'the pipe, and the diminution continues .until it meetsthe' corrugations nearthe end,

which corrugations project but'slightly'be A yo'nd the plane of the insetupper lportion of vthe kwall 1.

-' As stated the pipe has a plane inside. wall 18, and -a suitablek non-conducting air space 19 `between them.

In Fig." 3 a second sectionfof pipe is showny joined to the first described. The construction is the same as before. There a plane outer wall 20 and a planey inner wallf21 the edges of fwhich are connected together as stated. Of the second section. of'pipeA it` i will. be noted that the.; shoulder 23 projects inwardly and that it is the bottom.edgev of i the second section `which ,fis-illustratcddn li`i,f ,..3.y As the sectiony of `pipe first described has-a lbottom inner portion `of exactly the same construction as `the second sectionit may obviouslyjbe coupled with a third sec# tion andso on as desired. rl`he shoulder` 23 is of like form and `extent with the .shoulder 13 described, but passedv around inside the pipe section instead of; externally, and the same may be'said of the `the projecting lips y524i and 25,which are the same inform as lips' 1.5 and 16:v Thecrimped edge ofthe secondv I section marked 26 joins the outer and inner walls 20 and 21, `just as y.the walls, 1 an'dlS 'l' are` connected. The internal end portions gether as shown in Fig. 3.

of the second portion of Vpipel shown `in Fig. 3 and the end wall of that section interiorly are provided with corrugations arranged Vto receive the corrugations of the sides and ends of the first section. Y

1n operation the sections areV placed to- A slight pressure'causes the sides ot an inner section to bnlgeor bow inivardly, permitting the lips to'pass over each other and to Vbecome engaged as set forth. lt will be understood that when the sides of the inner section are pressed inwardly towards each other the total area oi the interior of the section is reduced and the ends of the section are drawn slightly towards each other. The sides may be readily bowed in the same manner to disconnect the sections. engage the corrugations also become engaged, and theV joint is closed throughout against the escape of warm air from the c joined sections of pipe.

Y Having -now ydescribed this invention and explained the mode' of its operation, l claim:-

1. A piece of double walled pipe comprisinga plane outer wall and a plane inner wall spaced apart, said pipe having sides greater in length than the width of the pipe, the edges of said walls being connected together to bound the openings into the interior of the pipe, one of saidwalls near one of said openings having a part between its ends formed into-a projecting inclined lip parallel with the edge 0I" the opening, and the endportions oi' the lip being graduallyT diminished in width. Y

2. `A piece oi'double walled pipe comprising a plane outer wall and a plane inner Wall spaced apart, said pipe having sides greater in length than the width of the pipe, the edges of said walls being connected together to bound the openings into the interior of the pipe, one of said walls near one of said openings having a part between its ends formed into a projecting inclined lip parallel with the edge of the opening, the end portions ot the lip being gradually diminished in width, and the. said wall being formed into a shoulder adjacent to the said lip and eX- tending from said inner to said outer wall.

3. A piece of double WalledV pipeV comprising a plane outer wall and a plane inner wall spaced apart, said pipe having sides greater in lengthv than the width of the pipe, the edges of said walls being connected together to bound the openings into the interior of the pipe, one of said-walls near one of said openings having a part between4 its ends formed into a projecting inclined lip parallel with the edge ofthe opening, the'end portions of the lip being gradually diminished in width,the said wallbeing formed r with a shoulder adjacent to the said lip and As the lips in length than the width ofthe: pipe, theV edges of said walls being connected together to bound the openings into the interior of the pipe, one ot' said walls near one vof said openings having a part between its ends formed into a projecting inclined lip parallel. with the edge of the opening, the said wall having near its end a portion provided with corrugations, and the endportion of the said lip being diminished in width to meet said corrugations. Y

In testimony whereof I aliix my signature.

VILLIAM T. TRUAX.

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